U.S. patent application number 16/482293 was filed with the patent office on 2019-11-14 for inspection chip and inspection system.
This patent application is currently assigned to Konica Minolta, Inc.. The applicant listed for this patent is Konica Minolta, Inc.. Invention is credited to Tomonori KANEKO, Takatoshi KAYA.
Application Number | 20190344261 16/482293 |
Document ID | / |
Family ID | 63169443 |
Filed Date | 2019-11-14 |
United States Patent
Application |
20190344261 |
Kind Code |
A1 |
KAYA; Takatoshi ; et
al. |
November 14, 2019 |
Inspection Chip and Inspection System
Abstract
An inspection chip according to the present invention is an
inspection chip for stirring liquid by a circular movement of a
bottom surface end, including a well main body for accommodating
the liquid and a side wall member arranged on a side surface of the
well main body. The bottom surface end has a bottom surface
structure in contact with a rotating member for allowing the bottom
surface end to perform the circular movement in a position leaning
from a center line of the well main body toward the side wall
member.
Inventors: |
KAYA; Takatoshi; (Inagi-shi,
Tokyo, JP) ; KANEKO; Tomonori; (Hachioji-shi, Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Konica Minolta, Inc. |
Chiyoda-ku, Tokyo |
|
JP |
|
|
Assignee: |
Konica Minolta, Inc.
Chiyoda-ku, Tokyo
JP
|
Family ID: |
63169443 |
Appl. No.: |
16/482293 |
Filed: |
February 6, 2018 |
PCT Filed: |
February 6, 2018 |
PCT NO: |
PCT/JP2018/003968 |
371 Date: |
July 31, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 21/6428 20130101;
B01L 2200/14 20130101; G01N 35/02 20130101; G01N 2201/0638
20130101; B01L 2200/025 20130101; B01L 2300/16 20130101; G01N
2021/0378 20130101; G01N 2201/023 20130101; B01L 2300/0627
20130101; B01L 2300/0851 20130101; B01L 3/508 20130101; B01L
2300/0858 20130101; B01L 2300/0832 20130101; G01N 21/658 20130101;
G01N 2021/6482 20130101; G01N 21/03 20130101; B01L 2200/06
20130101; B01L 2300/12 20130101; B01L 3/5082 20130101; G01N 21/01
20130101; G01N 21/648 20130101; B01L 2300/168 20130101; B01L
2300/06 20130101 |
International
Class: |
B01L 3/00 20060101
B01L003/00; G01N 21/01 20060101 G01N021/01; G01N 21/64 20060101
G01N021/64; G01N 21/65 20060101 G01N021/65 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 15, 2017 |
JP |
2017-025823 |
Claims
1. An inspection chip accommodating liquid therein for stirring the
liquid by circular movement of a bottom surface end, the inspection
chip comprising: a well main body for accommodating the liquid; and
a side wall member arranged on a side surface of the well main
body, wherein the bottom surface end of the well main body includes
a bottom surface structure in contact with a rotating member for
allowing the bottom surface end to perform the circular movement in
a position leaning from a center line of the well main body toward
the side wall member.
2. The inspection chip according to claim 1, wherein the bottom
surface structure is formed such that a position in contact with
the rotating member is present on an axis on which a center of
gravity of an entire inspection chip is present, the axis parallel
with the center line.
3. The inspection chip according to claim 1, wherein a shape of the
bottom surface structure is a curved surface.
4. The inspection chip according to claim 1, wherein the well main
body has a vertically long shape.
5. The inspection chip according to claim 4, wherein the well main
body has a tubular shape in which the bottom surface end is closed
by the bottom surface structure.
6. The inspection chip according to claim 5, wherein the well main
body is a cylinder.
7. The inspection chip according to claim 1, wherein the side wall
member includes an optical element.
8. The inspection chip according to claim 7, wherein the side wall
member includes a prism.
9. The inspection chip according to claim 8, wherein the well main
body has a through hole on a side surface, a metal film is formed
on one surface of the prism, and the metal film is exposed inside
the well main body in the through hole.
10. The inspection chip according to claim 9, wherein a ligand
molecule for capturing a substance to be detected is immobilized on
the metal film exposed to the inside of the well main body.
11. An inspection system using the inspection chip according to
claim 1, the system comprising: a light source that emits light to
the inspection chip; a detector that measures light to be measured
emitted from the inspection chip; and a stirring device that
includes the rotating member.
12. The inspection system according to claim 11, further
comprising: a conveyer that conveys the inspection chip, wherein
the conveyor conveys the inspection chip and arranges the
inspection chip in a predetermined position according to progress
of the inspection.
13. The inspection chip according to claim 2, wherein a shape of
the bottom surface structure is a curved surface.
14. The inspection chip according to claim 2, wherein the well main
body has a vertically long shape.
15. The inspection chip according to claim 2, wherein the side wall
member includes an optical element.
16. An inspection system using the inspection chip according to
claim 2, the system comprising: a light source that emits light to
the inspection chip; a detector that measures light to be measured
emitted from the inspection chip; and a stirring device that
includes the rotating member.
17. The inspection chip according to claim 3, wherein the well main
body has a vertically long shape.
18. The inspection chip according to claim 3, wherein the side wall
member includes an optical element.
19. An inspection system using the inspection chip according to
claim 3, the system comprising: a light source that emits light to
the inspection chip; a detector that measures light to be measured
emitted from the inspection chip; and a stirring device that
includes the rotating member.
20. The inspection chip according to claim 4, wherein the side wall
member includes an optical element.
Description
TECHNICAL FIELD
[0001] The present invention relates to an inspection chip
including a structure on a side surface thereof. The present
invention also relates to an inspection system using an inspection
chip including the structure on the side surface thereof.
BACKGROUND ART
[0002] In biochemical inspection, biochemical reactions such as
antigen-antibody reactions are used. For example, in
fluoroimmunoassay (FIA), a labeling substance containing a
fluorescent substance is bound to a substance to be detected
(antigen), and the substance to be detected is labeled with
fluorescence. Thereafter, the substance to be detected labeled with
the fluorescence is irradiated with excitation light, fluorescence
emitted from the fluorescent substance is detected, and an amount
of the substance to be detected and the like is specified from
intensity of the fluorescence. Among such FIAs, surface
plasmon-field enhanced fluorescence spectroscopy (SPFS) is known as
a method capable of detecting the substance to be detected with an
especially high degree of sensitivity.
[0003] In the SPFS, a first capturing body (for example, a primary
antibody) which specifically binds to the substance to be detected
is immobilized on a metal film to form a reaction site for
capturing the substance to be detected. For example, Patent
Literature 1 discloses an SPFS device provided with a well-type
inspection chip (sensor structure 22) in which a reaction site is
arranged on a bottom surface of a well (bottomed concave portion
for accommodating liquid). In the inspection chip, the well is
formed by fixing a well member having a through hole on a metal
film formed on a light transmissive dielectric member, and the
reaction site is arranged on the metal film forming the bottom
surface of the well. Then, by introducing a specimen (sample and
the like) which may contain the substance to be detected into this
well, the substance to be detected is bound to the first capturing
body immobilized on the metal film and forming the reaction site.
Then, a second capturing body is further bound to the substance to
be detected bound to the first capturing body by introducing the
second capturing body labeled with fluorescence (for example, a
secondary antibody) into the well. That is, the substance to be
detected is indirectly labeled with fluorescence. When the metal
film is irradiated with the excitation light from a side of a
dielectric member in this state, the fluorescent substance is
excited by an electric field enhanced by surface plasmon resonance
(SPR) to emit fluorescence. In the SPFS device disclosed in Patent
Literature 1, the fluorescence emitted from the fluorescent
substance passes through a liquid surface of the liquid in the well
and is detected by a detection unit arranged above the well.
CITATION LIST
Patent Literature
[0004] Patent Literature 1: WO 2012/157403 A
SUMMARY OF INVENTION
Technical Problem
[0005] As described above, in the inspection chip disclosed in
Patent Literature 1, since the metal film is formed on the bottom
surface of the well and the reaction site is arranged, a tip end of
a liquid delivery tool might be in contact with the metal film or
the reaction site to break them when removing liquid such as a
reagent in the well. Therefore, the tip end of the liquid delivery
tool cannot be pressed against the bottom surface of the well, and
it is difficult to sufficiently remove the liquid in the well.
Then, if the liquid such as the reagent is not removed sufficiently
and remains in the well, various reactions do not proceed properly,
and detection accuracy is lowered.
[0006] In addition, as described above, in the SPFS device
disclosed in Patent Literature 1, a detection unit is arranged
above the well and detects fluorescence which passes through the
liquid surface of the liquid in the well, so that a detection
result of the fluorescence might be affected by meniscus, air
bubbles present on the liquid surface or the like. If the detection
result of the fluorescence is affected by the meniscus, the air
bubbles or the like, the detection accuracy is lowered.
[0007] That is, in the inspection chip in which the reaction site
is provided on the bottom surface of the well as in the
conventional art, there is a problem that the detection accuracy is
lowered.
[0008] On the other hand, in order to sufficiently supply the
liquid such as the reagent to the reaction site and to perform the
reaction efficiently, it is necessary to stir the liquid
accommodated in the inspection chip. As a general stirring method,
stirring by circular movement (hereinafter, referred to as circular
movement stirring) is known. FIG. 1 is a schematic diagram for
illustrating circular movement of a conventional inspection chip
60x installed on a rotating body 99 of a stirring device. An upper
portion of FIG. 1 illustrates a side view of the inspection chip
60x installed on the rotating body 99 of the stirring device when
performing the circular movement stirring. A lower portion of FIG.
1 illustrates a schematic diagram of the inspection chip 60x as
seen from an opening side thereof when performing the circular
movement stirring. Meanwhile, in the lower portion of FIG. 1, for
convenience of illustration, the inspection chip 60x is indicated
by a straight line, and movement trajectories of a tip end 66b of
the inspection chip 60x which is in contact with the rotating body
99 to receive the circular movement of the rotating body 99 are
indicated by broken lines.
[0009] In the circular movement stirring, one end on the opening
side of the inspection chip 60x is fixed by a fixing member not
illustrated, and the other end on the bottom surface side of the
inspection chip 60x is installed on the rotating body 99 of the
stirring device as illustrated in FIG. 1. then, the inspection chip
60x is circularly moved along with the rotating body 99 which
performs the circular movement. In the conventional well-type
inspection chip 60x (for example, test tube and the like), the
inspection chip 60x has a symmetrical structure, and the center of
gravity G1 in a state in which the liquid such as the reagent is
accommodated and the tip end 66b in contact with the rotating body
99 to receive the circular movement of the rotating body 99 are
located on the same axis in a length direction (vertical direction
in FIG. 1) of the inspection chip 60x, so that, as illustrated in
the lower portion of FIG. 1, both exhibit the same movement
trajectory and the inspection chip 60x may perform stable circular
movement along with the circular movement of the rotating body
99.
[0010] However, if the reaction site is to be provided in a
position other than the bottom surface of the well in order to
solve the above-described problem that the detection accuracy is
lowered occurring when the inspection chip provided with the
reaction site on a bottom surface of the well is used, it is also
necessary to move the dielectric member and the like along with
this, and the structure of the inspection chip becomes asymmetric.
For example, a case of using the inspection chip including the
reaction site on a side surface thereof is herein described.
[0011] FIG. 2 is a schematic diagram for illustrating circular
movement of an inspection chip 60y installed on the rotating body
99 of the stirring device including time reaction site on a side
surface thereof. An upper portion of FIG. 2 illustrates a side view
of the inspection chip 60y installed on the rotating body 99 of the
stirring device when performing the circular movement stirring. A
lower portion of FIG. 2 illustrates a schematic diagram of the
inspection chip 60y as seen from an opening side thereof when
performing the circular movement stirring. Meanwhile, in the lower
portion of FIG. 2, for convenience of illustration, the inspection
chip 60y is indicated by a straight line, and movement trajectories
of a tip end 66b of the inspection chip 60y which is in contact
with the rotating body 99 to receive the circular movement of the
rotating body 99 and the center of gravity G2 of the inspection
chip 60y in a state of accommodating the liquid such as the reagent
are indicated by broken lines.
[0012] As illustrated in FIG. 2, in the inspection chip 60y
including the reaction site on the side surface thereof, the
inspection chip 60y has an asymmetrical structure, and the center
of gravity G2 in a state in which the liquid such as the reagent is
accommodated and the tip end 66b of the inspection chip 60y in
contact with the rotating body 99 to receive the circular movement
of the rotating body 99 are located on the same axis in a length
direction (vertical direction in FIG. 2) of the inspection chip 60y
so as to be spaced apart from each other, so that, as illustrated
in the lower portion of FIG. 2, both exhibit different movement
trajectories and the circular movement of the inspection chip 60y
is affected by this and becomes unstable. Specifically, the
inspection chip 60y might fall from the stirring device. Also, even
in a case where the inspection chip 60y does not fall from the
stirring device, the liquid such as the reagent in the inspection
chip 60y cannot be efficiently stirred, and there is a possibility
that the liquid such as the reagent in the inspection chip 60y does
not form a so-called vortex even if the stirring is performed and
it cannot be expected that the liquid such as the reagent is
sufficiently supplied to the reaction site.
[0013] That is, in the conventional technology, it was not possible
to simultaneously realize further improvement in detection accuracy
of the substance to be detected and stable and efficient
stirring.
Solution to Problem
[0014] An inspection chip according the present invention is an
inspection chip accommodating liquid therein for stirring the
liquid by circular movement of a bottom surface end, the inspection
chip including a well main body for accommodating the liquid, and a
side wall member arranged on a side surface of the well main body,
in which the bottom surface end of the well main body includes a
bottom surface structure in contact with a rotating member for
allowing the bottom surface end to perform the circular movement in
a position leaning from a center line of the well main body toward
the side wall member.
[0015] An inspection system according to the present invention is
an inspection system using the inspection chip according to the
present invention, the system including a light source which emits
light to the inspection chip, a detection unit for measuring light
to be measured emitted from the inspection chip, and a stirring
device including the rotating member.
Advantageous Effects of Invention
[0016] According to the present invention, it is possible to
simultaneously achieve further the improvement in detection
accuracy of the substance to be detected and the stable and
efficient stirring.
BRIEF DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is a schematic diagram for illustrating circular
movement of a conventional inspection chip installed on a rotating
body of a stirring device.
[0018] FIG. 2 is a schematic diagram for illustrating circular
movement of a conventional inspection chip installed on the
rotating body of the stirring device including a structure on a
side surface thereof.
[0019] FIG. 3 is a schematic diagram illustrating a configuration
of a biochemical inspection system.
[0020] FIG. 4A is a perspective view of an inspection chip. FIG. 4B
is a perspective view of a well main body. FIG. 4C is a perspective
transparent view of the well main body.
[0021] FIG. 5 is a schematic diagram illustrating a structure of a
side wall member.
[0022] FIG. 6 is a schematic diagram when the inspection chip is
seen from a first opening side.
[0023] FIG. 7 is a block diagram of a control arithmetic unit.
[0024] FIG. 8 is a schematic diagram for illustrating circular
movement of the inspection chip installed on a rotating body of a
stirring device.
[0025] FIG. 9 is a flowchart for illustrating operation of the
biochemical inspection system.
DESCRIPTION OF EMBODIMENTS
[0026] Hereinafter, a mode for carrying out the present invention
is described with reference to the drawings. This embodiment is a
biochemical inspection system adopting a continuous mode in which a
plurality of measurement units for performing respective steps
forming one inspection is sequentially arranged in a production
line, capable of substantially simultaneously performing a
plurality of inspections by sequentially introducing a plurality of
inspection chips while the respective steps are sequentially
performed and the inspection progresses by progress of the
inspection chip along the production line. However, the present
invention is not limited to the continuous mode. For example, it is
also possible to adopt a non-continuous mode in which the
respective steps forming one inspection are performed in the same
position, and the progress of the inspection is not dependent on
the progress of the inspection chip.
[0027] Meanwhile, although a method using SPFS as a biochemical
inspection is adopted in this embodiment, the present invention is
not limited to the method using the SPFS. For example, methods such
as surface plasmon resonance (SPR), general fluorescence
immunoassay and the like may also be adopted. A type and a mode of
the inspection are not limited, and in a case where it is necessary
to use an asymmetric inspection chip, an effect of simultaneously
realizing further improvement in detection accuracy of a substance
to be detected and stable and efficient stirring may be
obtained.
[0028] (Biochemical Inspection System)
[0029] FIG. 3 is a schematic diagram illustrating a configuration
of a biochemical inspection system A according to this embodiment.
The biochemical inspection system A is a system for performing the
biochemical inspection using the SPFS. Specifically, the
biochemical inspection system A captures a substance to be detected
by a first capturing body immobilized on a metal film and labels
the substance to be detected with fluorescence by binding a second
capturing body labeled with fluorescence by a fluorescent substance
to the substance to be detected captured by the first capturing
body. Thereafter, the metal film is irradiated with excitation
light to generate an enhanced electric field based on surface
plasmon resonance in the vicinity of the metal film, and
fluorescence emitted from the fluorescent substance excited by the
enhanced electric field is detected to measure presence or an
amount of the substance to be detected.
[0030] As illustrated in FIG. 3, the biochemical inspection system
A is formed of a vibration unit 10, a light projection unit 20, a
liquid delivery/conveyance unit 30. a detection unit 40, and a
control arithmetic unit 50, and is configured to irradiate an
inspection chip arranged in the vibration unit 10 with the
excitation light by the light projection unit 20 to detect
fluorescence emitted from the inspection chip by the detection unit
40. A specific configuration of each unit is hereinafter
described.
[0031] (Vibration Unit)
[0032] The vibration unit 10 is provided with stirring devices not
illustrated which stir liquid accommodated in inspection chips 60a,
60c, and 60d by rotary vibration in positions 10a, 10c, and 10d
corresponding to the inspection chips 60a, 60c, and 60d. The
stirring device is arranged in a position not interfering with an
optical path of the excitation light, fluorescence, plasmon
scattered light and the like and includes an eccentric rotating
body. The rotating body performs the rotary vibration in a
contacting state with the inspection chip, thereby applying rotary
vibration in a circumferential direction to the inspection chip to
stir the liquid accommodated in the inspection chip. However, the
stirring device is not limited to that including the eccentric
rotating body as long as this may stir the liquid accommodated in
the inspection chip by applying the rotary vibration to the
inspection chip.
[0033] By stirring the liquid accommodated in the inspection chip
by the stirring device, reaction, cleaning and the like at each
step in the biochemical inspection may be performed efficiently.
From the viewpoint of efficiently stirring the liquid in the
inspection chip, the stirring device preferably applies the rotary
vibration to the inspection chip at an inherent frequency of the
inspection chip accommodating the liquid, or at vibration
frequencies around the same. It is also possible to apply the
rotary vibration to the inspection chip while sequentially
switching different inherent frequencies (n-th order inherent
frequency and m-th order inherent frequency, n and m being positive
integers). Meanwhile, the position in which the stirring device is
provided is not limited to the above-described position, and it is
also possible to change the installation position or the number as
needed or to provide the stirring devices so as to correspond to
all the inspection chips according to operational contents and the
like at each step.
[0034] (Light Projection Unit)
[0035] The light projection unit 20 formed of a light source unit
and a first angle adjustment unit (both are not illustrated)
irradiates the inspection chip with the excitation light.
[0036] The light source unit formed of a light source, a beam
shaping optical system, an APC mechanism, and a temperature
adjusting mechanism irradiates the inspection chip with the
excitation light. FIGS. 4A to 4C are schematic diagrams
illustrating a structure of the inspection chip 60. Although the
structure of the inspection chip 60 is to be described later in
detail, as illustrated in FIG. 4A. the inspection chip 60 is formed
of a well main body 61 and a side wall member 62, and as
illustrated in FIGS. 4B and 4C, a second opening 64 is provided on
a side wall of the well main body 61 adjacent to the side wall
member 62. FIG. 5 is a partially enlarged cross-sectional view of
the vicinity of the second opening 64 in a cross-section in a
height direction (vertical direction in FIG. 4) of the inspection
chip 60, a schematic diagram illustrating a structure of the side
wall member 62. Although the structure of the side wall member 62
is to be described later in detail, as illustrated in FIG. 5, the
side wall member 62 is formed of a prism 71, a metal film 75, and a
capturing film 76, and the capturing film 76 is exposed in the
second opening 64 to form a reaction site 77.
[0037] FIG. 6 illustrating a cross-section of the inspection chip
60 is a schematic diagram illustrating light incident on the
inspection chip 60 and light emitted from the inspection chip 60.
As illustrated in FIG. 6, the light source unit irradiates the
prism 71 of the inspection chip 60 with excitation light 91 having
constant wavelength and light amount such that a shape of an
irradiation spot on a reflective surface 73 of the prism 71 is
substantially circular. A size of the irradiation spot is
preferably smaller than the reaction site 77.
[0038] A type of the light source is not especially limited, and
is, for example, a laser diode (LD). Other examples of the light
source include a light emitting diode, a mercury lamp, and other
laser light sources. In a case where the light emitted from the
light source is not a beam, the light emitted from the light source
is converted into the beam by a lens, a mirror, a slit and the
like. Also, in a case where the light emitted from the light source
is not monochromatic light, the light emitted from the light source
is converted into the monochromatic light by a diffraction grating
and the like. Furthermore, in a case where the light emitted from
the light source is not linear polarized light, the light emitted
from the light source is converted into the linear polarized light
by a polarizer and the like.
[0039] The beam shaping optical system is formed of, for example, a
collimator, a band pass filter, a linear polarization filter, a
half wavelength plate, a slit, a zoom means and the like. However,
the beam shaping optical system may also be formed to include only
a part of them. The collimator collimates the excitation light
emitted from the light source. The band pass filter makes the
excitation light emitted from the light source narrow band light
having only a central wavelength. This is because the excitation
light emitted from the light source has a slight wavelength
distribution width. The linear polarization filter makes the
excitation light emitted from the light source completely linear
polarized light. The half wavelength plate adjusts a polarization
direction of the excitation light so that a P wave component is
incident on the reflective surface 73. The slit and zoom means
adjust a beam diameter, a contour shape and the like of the
excitation light so that the shape of the irradiation spot on the
reflective surface 73 becomes a circle of a predetermined size.
[0040] The APC mechanism controls the light source so that an
output of the light source is constant. Specifically, the APC
mechanism detects a light amount of light branched from the
excitation light by a photodiode or the like, and controls input
energy by a recurrent circuit to control the output of the light
source constant.
[0041] The temperature adjusting mechanism is, for example, a
heater, a Peltier element and the like. The wavelength and energy
of the light emitted from the light source might fluctuate
depending on temperature, so that the temperature adjusting
mechanism maintains the temperature of the light source constant,
thereby controlling the wavelength and energy of the light emitted
from the light source constant.
[0042] The first angle adjustment unit relatively rotates an
optical axis of the excitation light 91 and the inspection chip 60
to adjust an incident angle .alpha. of the excitation light 91 on
the reflective surface 73.
[0043] For example, the first angle adjustment unit rotates the
light source unit about an axis in the height direction of the
inspection chip 60 (an axis perpendicular to a paper surface in
FIG. 6) to scan the incident angle .alpha.. As a result, even if
the incident angle .alpha. fluctuates due to the above-described
scanning, the position of the irradiation spot of the excitation
light 91 on the reflective surface 73 is maintained with
substantially no change.
[0044] As described above, when the first angle adjustment unit
scans the incident angle .alpha. of the excitation light 91, an
enhancement angle is specified in the detection unit 40 to be
described later. The enhancement angle is an angle being an
incident angle when an amount of plasmon scattered light 94 having
the same wavelength as that of the excitation light 91 passing
through the reflective surface 73 to be emitted on a side of the
well main body 61 of the inspection chip 60 is the maximum in a
case where the reflective surface 73 is irradiated with the
excitation light 91. The enhancement angle is set as the incident
angle .alpha. of the excitation light 91 at the time of optical
blank measurement and fluorescence value measurement to be
described later. Meanwhile, an incident condition of the excitation
light 91 such as the enhancement angle is roughly determined by
design elements of the inspection chip 60 (for example, a material
and a shape of the prism 71, a film thickness of the metal film 75,
a wavelength of the excitation light 91 and the like), a refractive
index of the liquid accommodated in the inspection chip 60 and the
like, but this might fluctuate depending on an error in shape of
the prism 71, a composition of the liquid accommodated in the
inspection chip 60 (for example, a type and an amount of
fluorescent substance and the like), so that it is preferable to
specify an optimum enhancement angle for each inspection.
[0045] (Detection Unit)
[0046] The detection unit 40 is formed of a first lens, an optical
filter, a second lens, a position switching unit, and a light
receiving sensor (all are not illustrated) and detects fluorescence
93 and the plasmon scattered light 94 emitted from the inspection
chip 60.
[0047] The first lens is, for example, a condensing lens, and
condenses light emitted from the vicinity of the reaction site 77.
The second lens is, for example, an image forming lens, and forms
an image of the light condensed by the first lens on a light
receiving surface of the light receiving sensor. An optical path
between the first lens and the second lens is a substantially
parallel optical path.
[0048] The optical filter is arranged on the optical path between
the first lens and the second lens by a position switching unit in
a case of detecting the fluorescence 93. The optical filter is, for
example, a filter including a multilayer film which reflects a
predetermined light component, or a color glass filter which
absorbs a predetermined light component, and removes an excitation
light component such as the excitation light 91 and the plasmon
scattered light 94 out of the light condensed by the first lens and
guides only the fluorescence 93 to the light receiving sensor. As a
result, in the light receiving sensor, the fluorescence 93 may be
detected at a high signal (S)/noise (N) ratio. Examples of the
optical filter include an excitation light reflecting filter, a
short wavelength cutting filter, and a band pass filter.
[0049] In a case where the plasmon scattered light 94 is detected,
the optical filter is arranged outside the optical path between the
first lens and the second lens. In this case, the enhancement angle
which is the incident angle when the light amount of the plasmon
scattered light 94 is the maximum is specified.
[0050] The position switching unit arranges the optical filter on
the optical path between the first lens and the second lens or
outside the same as needed. Specifically, in a case of detecting
the fluorescence 93, the optical filter is arranged on the optical
path, and in a case of detecting the plasmon scattered light 94,
the optical filter is arranged outside the optical path.
[0051] The light receiving sensor detects the fluorescence 93 and
the plasmon scattered light 94. The light receiving sensor is, for
example, a photomultiplier tube (PMT), an avalanche photodiode
(APD) or the like. However, the light receiving sensor is not
limited to them, and may be any sensor capable of detecting weak
fluorescence 93 and having high sensitivity.
[0052] The detection unit 40 may also be configured to detect
reflected light 92 of the excitation light 91 instead of detecting
the plasmon scattered light 94. For example, this may be configured
to detect the reflected light 92 by the above-described light
receiving sensor or by a light receiving sensor (for example, a
photodiode) for detecting the reflected light separately provided.
In this case, when the first angle adjustment unit of the light
projection unit 20 scans the incident angle .alpha. of the
excitation light 91, the detection unit 40 specifies a resonance
angle in place of the enhancement angle, and this is set as the
incident angle .alpha. of the excitation light 91 at the time of
the optical blank measurement and the fluorescence value
measurement to be described later. The resonance angle is an angle
which is the incident angle when the light amount of the reflected
light 92 of the excitation light 91 reflected by the reflective
surface 73 is the minimum in a case where the reflective surface 73
is irradiated with the excitation light 91. Meanwhile, the
resonance angle is in the close vicinity of the enhancement
angle.
[0053] Also, the light projection unit 20 and the light receiving
sensor are arranged at the same height as the inspection chip 60.
As a result, the biochemical inspection system may be made compact.
However, the light projection unit 20 and the light receiving
sensor are not necessarily arranged at the same height as the
inspection chip 60. For example, it is also possible to freely
change positions of the light projection unit 20 and the light
receiving sensor using a mirror or the like.
[0054] (Liquid Delivery/Conveyance Unit)
[0055] The liquid delivery/conveyance unit 30 is formed of a liquid
delivery means and a conveyance means (both are not illustrated).
The liquid delivery means supplies liquid such as a reagent to the
inspection chip, and recovers the liquid accommodated in the
inspection chip as needed. The conveyance means moves the
inspection chip to arrange in an appropriate position as
needed.
[0056] The liquid delivery means is formed of a reagent chip, a
pipette unit, and a first moving mechanism (all are not
illustrated).
[0057] The reagent chip is a container capable of accommodating a
sample, a sample diluting solution, a measuring buffer solution, a
cleaning solution, a labeling solution for assigning a fluorescent
label to the substance to be detected and the like. Types of the
sample and the substance to be detected are not especially limited.
Examples of the sample include body fluid such as blood, serum,
plasma, cerebrospinal fluid, urine, nostril fluid, saliva, and
semen, and tissue extracts. Examples of the substance to be
detected include nucleic acids (DNA and RNA), proteins
(polypeptides, oligopeptides and the like), amino acids,
carbohydrates, lipids, and modified molecules thereof. The sample
diluting solution includes, for example, bovine serum albumin
(BSA), Antifoam SI, NaN.sub.3, carboxymethyl-dextran (CMD), human
anti-mouse antibodies (HAMA) inhibitor, phosphate buffered saline
with Tween 20 (PBST) and the like. The measuring buffer solution
includes, for example, BSA, Antifoam SI, NaN.sub.3, and PBST. The
cleaning solution includes, for example, Antifoam SI, NaN.sub.3,
and PBST. The labeling solution includes, for example, a secondary
antibody labeled with a fluorescent substance and PBST. The reagent
chip is usually such that a plurality of containers is arranged
according to the type of liquid, or a plurality of containers is
integrated.
[0058] The pipette unit is formed of a syringe pump and a nozzle.
The syringe pump includes a syringe, a plunger capable of
reciprocating in the syringe, and a drive mechanism, and sucks or
discharges the liquid quantitatively by reciprocating movement of
the plunger. The drive mechanism is a means for reciprocating the
plunger and is formed of, for example, a stepping motor. One end of
the nozzle is connected to the syringe pump. A pipette chip is
mounted on the other end of the nozzle not connected to the syringe
pump. However, it is also possible to supply the liquid such as the
reagent directly into the inspection chip by the nozzle, or to
directly recover the liquid accommodated in the inspection chip by
the nozzle without using the nozzle.
[0059] The first moving mechanism moves the nozzle and arranges the
same in a predetermined position. For example, the first moving
mechanism freely moves the nozzle in two directions: vertical and
horizontal directions. Examples of the first moving mechanism
include one formed of a robot arm and a biaxial stage or a
turntable which may move up and down.
[0060] The conveyance means is formed of an inspection chip holding
unit and a second moving mechanism (both are not illustrated).
[0061] The inspection chip holding unit is for holding the
inspection chip 60, and is fixed to the second moving mechanism or
configured to be removable. The second moving mechanism moves the
inspection chip holding unit to arrange the inspection chip 60 held
by the inspection chip holding unit to appropriate positions as
needed such as the positions 10a to 10e corresponding to the
respective measurement units which perform the individual steps
forming the inspection. Examples of the second moving mechanism
include a conveyor and a rotating stage. However, it is not
necessary to provide the second moving mechanism in a case of
adopting the non-continuous mode to perform the respective steps
forming one inspection in the same position without adopting the
continuous mode in which a plurality of inspections may be
substantially simultaneously performed. For example, it is also
possible to configure such that the second moving mechanism is
omitted and only the inspection chip holding unit is provided to
hold the inspection chip 60. Also, even in a ease of adopting the
continuous mode, if it is not necessary to move the inspection chip
60 in accordance with the progress of the inspection, it is also
possible to provide a plurality of inspection chips 60
corresponding to the measurement units performing the respective
steps forming one inspection and transfer the liquid such as the
reagent in the inspection chip 60 to the inspection chip 60
corresponding to a next measurement unit by the liquid delivery
means and the like instead of moving the inspection chip 60 after
operation in one measurement unit is completed. In this case also,
the second moving mechanism may be omitted, and only the inspection
chip holding unit is provided to hold each inspection chip 60.
[0062] (Control Arithmetic Unit)
[0063] FIG. 7 is a block diagram of the control arithmetic unit 50.
As illustrated in FIG. 7, the control arithmetic unit 50 is formed
of a CPU 51, a light projection control unit 52, a liquid delivery
drive control unit 53, a liquid delivery movement control unit 54,
a conveyance control unit 55, a detection control unit 56, and an
arithmetic unit 57.
[0064] The CPU 51 controls entire measurement and allows each
control unit or arithmetic unit to be described later to operate as
needed. The light projection control unit 52 controls the light
projection unit 20 and applies the excitation light to a
predetermined position. The liquid delivery drive control unit 53
controls the pipette unit of the liquid delivery means of the
liquid delivery/conveyance unit 30, and sucks or discharges
predetermined liquid by a predetermined amount. The liquid delivery
movement control unit 54 controls the first moving mechanism of the
liquid delivery means of the liquid delivery/conveyance unit 30 and
arranges the nozzle in a predetermined position. The conveyance
control unit 55 controls the conveyance means of the liquid
delivery/conveyance unit 30, and arranges the inspection chip in an
appropriate position as needed. The detection control unit 56
controls the detection unit 40, and detects the plasmon scattered
light or fluorescence as needed. The arithmetic unit 57 specifies
the enhancement angle on the basis of the light amount of the
plasmon scattered light, performs quantitative measurement such as
calculation of concentration of the substance to be detected on the
basis of the light amount of fluorescence, and performs other
correction processing of data and the like.
[0065] (Inspection Chip)
[0066] FIGS. 4A to 4C are schematic diagrams illustrating a
structure of the inspection chip 60. FIG. 4A is a perspective view
of the inspection chip 60. As illustrated in FIG. 4A, the
inspection chip 60 is formed of the well main body 61 and the side
wall member 62. The well main body 61 has a bottomed structure
capable of accommodating the liquid.
[0067] (Well Main Body)
[0068] FIG. 4B is a perspective view of the well main body 61, and
FIG. 4C is a perspective transparent view of the well main body 61.
As illustrated in FIGS. 4B and 4C, the well main body 61 includes
the first opening 63 on one end, the second opening 64 on the side
wall adjacent to the side wall member 62, and a bottom surface
structure 66 on a bottom surface end opposite to the side of the
first opening 63. Also, the well main body 61 is a substantial
cylinder in which an outer wall on the side on which the side wall
member 62 is arranged is ground to be a flat surface in accordance
with a width of the side wall member 62 and the bottom surface end
is closed by the bottom surface structure 66. A space in the well
main body 61 connected to the first opening 63 and the second
opening 64 is a liquid accommodation unit 65 for accommodating the
liquid such as the reagent. A shape of the well main body 61 is not
limited to the cylinder, and may be, for example, a rectangular
tube having a square cross-section or one having an asymmetric
cross-section. Especially, in a case where the well main body 61
has a vertically long shape, an effect of simultaneously realizing
further improvement in detection accuracy of the substance to be
detected and stable and efficient stirring is remarkable. Also, it
is sufficient that a shape of the outer wall of the well main body
61 on the side on which the side wall member 62 is arranged may fix
the side wall member 62 and this is not limited to the flat
surface.
[0069] The well main body 61 is formed of a material transparent to
light having the wavelength of the excitation light 91 and light
having the wavelength of the fluorescence 93, and is formed of, for
example, a resin or glass. However, a part of the well main body 61
may be formed of a material opaque to the light having the
wavelength of the excitation light 91 and the light having the
wavelength of the fluorescence 93 as long as measurement by an
inspection method to be described later is not interfered.
[0070] The bottom surface structure 66 is a curved surface in which
a tip end 66a leans toward the side wall member 62. FIG. 6 is a
schematic diagram when the inspection chip 60 is seen from the
first opening 63 side. As illustrated in FIG. 6, the tip end 66a is
located not at the symmetry center c of the cross-section of the
well main body 61 but at a tip end position x leaning from the
symmetry center c toward the side wall member 62. The tip end
position x and the center of gravity of the inspection chip 60 in a
state of accommodating the liquid such as the reagent (hereinafter
simply referred to as the "center of gravity of the inspection chip
60") G2 are located on the same axis in a length direction of the
inspection chip 60. FIG. 8 is a schematic diagram for illustrating
circular movement of the inspection chip 60 installed on a rotating
body 99 of the stirring device. An upper portion of FIG. 8
illustrates a side view of the inspection chip 60 installed on the
rotating body 99 of the stirring device when the liquid in the
inspection chip 60 is stirred. A lower portion of FIG. 8
illustrates a schematic diagram when the inspection chip 60 is seen
from the first opening 63 side when the liquid in the inspection
chip 60 is stirred. As illustrated in FIG. 8, since the inspection
chip 60 and the rotating body 99 are in contact with each other at
the tip end 66a, when the tip end 66a is located on the axis in the
length direction of the inspection chip 60 where the center of
gravity G2 of the inspection chip 60 is present, as illustrated in
the lower portion of FIG. 8, the center of gravity G2 of the
inspection chip 60 and the tip end 66a perform the circular
movement with the same movement trajectory, and the inspection chip
60 may perform stable circular movement with the circular movement
of the rotating body 99. Meanwhile, in the lower portion of FIG. 8,
for convenience of illustration, the inspection chip 60 is
indicated by a straight line, and the movement trajectories of the
center of gravity of the inspection chip 60 and the tip end 66a are
indicated by broken lines.
[0071] As described above, when the inspection chip 60 may perform
the stable circular movement, the inspection chip 60 does not fall
from the stirring device, so that it becomes possible to
efficiently stir the liquid such as the reagent accommodated in the
inspection chip 60 by the circular movement and sufficiently supply
the liquid such as the reagent to the reaction site to be described
later.
[0072] The bottom surface structure 66 is not limited to the curved
surface, and may be, for example, a pyramid having a tip end at the
tip end position x or a flat surface having a protrusion at the tip
end position x. That is, it is sufficient that the bottom surface
structure 66 is configured to be in contact with the rotating body
99 of the stirring device at the tip end position x to receive the
circular movement. Also, from the viewpoint of stability when being
mounted on the rotating body 99, the bottom surface structure 66
preferably has the same shape as that of the surface of the
rotating body 99 which is in contact.
[0073] Also, in this embodiment, the tip end position x and the
center of gravity G2 of the inspection chip 60 are located on the
same axis in the length direction of the inspection chip 60, but
the tip end position x is not limited thereto, and it is sufficient
that this leans toward the side wall member 62 from the center
position (in this embodiment, the symmetry center c) of the
cross-section of the well main body 61. For example, due to a
weight and the like of the side wall member 62, it is sometimes
impossible to arrange the tip end position x and the center of
gravity G2 of the inspection chip 60 on the same axis in the length
direction of the inspection chip 60 because of the structure of the
inspection chip 60. In such a case, it is not necessary that the
tip end position x and the center of gravity G2 of the inspection
chip 60 be located on the same axis in the length direction of the
inspection chip 60, and if the tip end position x is arranged to
lean toward the side wall member 62, it is possible to obtain an
effect of making the circular movement of the inspection chip 60
stable and efficiently stirring the liquid such as the reagent
accommodated in the inspection chip 60.
[0074] Also, as described above, the center of gravity of the
inspection chip 60 is exactly the center of gravity of the
inspection chip 60 in a state of accommodating the liquid such as
the reagent, but it is also possible that the center of gravity of
the inspection chip 60 is the center of gravity of the inspection
chip 60 itself for the convenience of the manufacture and the
like.
[0075] (Side Wall Member)
[0076] FIG. 5 is a partially enlarged cross-sectional view of the
vicinity of the second opening 64 in a cross-section in a height
direction (vertical direction in FIG. 4) of the inspection chip 60,
a schematic diagram illustrating a structure of the side wall
member 62. As illustrated in FIG. 5, the side wall member 62 is
formed of the prism 71, the metal film 75, and the capturing film
76, and the capturing film 76 is exposed in the second opening 64
to form the reaction site 77. The side wall member 62 is bonded to
the well main body 61 via a bonding layer not illustrated so that
the second opening 64 may be closed without leakage of the liquid
such as the reagent accommodated in the inspection chip 60.
However, the side wall member 62 may also be bonded to the well
main body 61 by laser welding, ultrasonic welding, pressure bonding
using a clamp member or the like without using the bonding
layer.
[0077] The prism 71 is an optical element made of a dielectric
transparent to the excitation light 91 and has not a little
birefringence characteristic. The material of the prism 71 includes
the resin and glass and this is preferably the resin having a
refractive index of 1.4 to 1.6 and small birefringence.
[0078] FIG. 6 is a schematic diagram of the inspection chip 60 as
seen from the side of the first opening 63, the schematic diagram
illustrating the light incident on the inspection chip 60 and the
light emitted from the inspection chip 60. As illustrated in FIG.
6, the prism 71 is a columnar body a bottom surface of which has a
trapezoidal shape in which a surface corresponding to one bottom of
the trapezoidal shape is the reflective surface 73, a surface
corresponding to one leg is an incident surface 72, and a surface
corresponding to the other leg is a light emitting surface 74. The
excitation light 91 emitted from the light projection unit 20 is
incident on the incident surface 72. The prism 71 is configured
such that the light passing through the incident surface 72 to
enter the prism 71 is reflected by the reflective surface 73, and
the reflected light 92 reflected by the reflective surface 73
passes through the emitting surface 74 to emit out of the prism 71.
However, the shape of the prism 71 is not limited to the columnar
body having the trapezoidal bottom surface, and may be, for
example, a triangular prism or a semi-cylinder. Also, it is
preferable that the reflective surface 73 is a flat surface.
[0079] Also, in a case where the light source of the excitation
light 91 is a laser diode (LD), when the excitation light 91
returns to the LD, an excited state of the LD is disturbed, and the
wavelength and output of the excitation light 91 fluctuate, so that
the incident surface 72 is formed so that the excitation light 91
does not return to the light projection unit 20, and an angle with
the reflective surface 73 is set so that the excitation light 91 is
not perpendicularly incident on the incident surface 72. In this
embodiment, the angle between the incident surface 72 and the
reflective surface 73 and the angle between the reflective surface
73 and the emitting surface 74 are both about 80 degrees.
[0080] The metal film 75 is formed on the reflective surface 73 of
the prism 71. A material of the metal film 75 is not especially
limited as long as this is metal capable of causing the surface
plasmon resonance. Examples of the material of the metal film 75
include gold, silver, copper, aluminum, and alloys thereof. A
method of forming the metal film 75 is not especially limited.
Examples of the method of forming the metal film 75 include
sputtering, vapor deposition, and plating. Although a thickness of
the metal film 75 is not especially limited, this is preferably
within a range of 30 to 70 nm.
[0081] The capturing film 76 is a region in which the first
capturing body which specifically binds to the substance to be
detected is immobilized on the metal film 75. A type of the first
capturing body is not especially limited as long as this may
specifically bind to the substance to be detected. Examples of the
first capturing body include an antibody (primary antibody) capable
of specifically binding to the substance to be detected or a
fragment thereof a nucleic acid, an enzyme and the like.
[0082] The reaction site 77 is a region of the capturing film 76
exposed to the liquid accommodation unit 65 of the well main body
61 in the second opening 64. In the reaction site 77, the first
capturing body which is immobilized on the metal film 75 and forms
the capturing film 76 specifically binds to the substance to be
detected present in the sample to selectively capture the substance
to be detected. From the viewpoint of detection accuracy, it is
preferable that the surface on which the reaction site 77 is
formed, that is, the surface of the region of the metal film 75
corresponding to the reaction site 77 in this embodiment is a flat
surface. It is also possible to apply a protective layer for
maintaining a capturing ability of the first capturing body for a
long time on the reaction site 77.
[0083] A size of the reaction site 77 is not especially limited. In
a case where the capturing film 76 has such a size to close the
second opening 64, the size of the reaction site 77 is defined by
the second opening 64. As a result, the size of the reaction site
77 may be adjusted easily with a high degree of accuracy. On the
other hand, in a case where the capturing film 76 is smaller than
the second opening 64, the size of the capturing film 76 directly
becomes the size of the reaction site 77.
[0084] Also, it is preferable that the reaction site 77 is arranged
in a position away from the bottom surface on the bottom surface
structure 66 side of the well main body 61. As a result, the liquid
such as the reagent in the liquid accommodation unit 65 may be
supplied to the reaction site 77 to perform the reaction
efficiently. Also, when detecting the fluorescence 93, it is
possible to prevent the detection accuracy from being lowered by
noise caused by the bottom surface on the bottom surface structure
66 side of the well main body 61.
[0085] (Operation of Biochemical Inspection System)
[0086] FIG. 9 is a flowchart for illustrating operation of the
biochemical inspection system A. The operation of the biochemical
inspection system A is described with reference to FIG. 9.
[0087] First, preparation for measurement is performed (step S10).
Specifically, by control of the control arithmetic unit 50, the
liquid delivery/conveyance unit 30 moves a target inspection chip
60 to the position 10a of the biochemical inspection system A
(refer to FIG. 3), and mount the inspection chip 60 on the rotating
body of the stirring device corresponding to the position 10a.
Then, the cleaning solution is supplied to the inspection chip 60
by the liquid delivery/conveyance unit 30, and the inside of the
liquid accommodation unit 65 is cleaned while the vibration unit 10
stirs the liquid in the inspection chip 60. At that time, in a case
where the protective layer for maintaining the capturing ability of
the first capturing body for a long time is applied on the reaction
site 77, the protective layer is also removed. Thereafter, the
cleaning solution in the inspection chip 60 is recovered by the
liquid delivery/conveyance unit 30, and the measuring buffer
solution is newly supplied into the inspection chip 60.
[0088] Next, the inspection chip 60 is irradiated with the
excitation light, and enhancement measurement for specifying the
enhancement angle and optical blank value measurement for measuring
an optical blank value are performed (step S20). Specifically, by
the control of the control arithmetic unit 50, the liquid
delivery/conveyance unit 30 arranges the target inspection chip 60
in the position 10b (refer to FIG. 3) of the biochemical inspection
system A, and the light projection unit 10 irradiates the region of
the reflective surface 73 corresponding to the reaction site 77 of
the inspection chip 60 with the excitation light 91 while scanning
the incident angle .alpha.. At the same time, the detection unit 40
detects the plasmon scattered light 94 emitted to the inside of the
inspection chip 60 from the metal film 75 irradiated with the
excitation light 91. The control arithmetic unit 50 obtains data
including a relationship between the incident angle .alpha. of the
excitation light 91 and intensity of the plasmon scattered light
94, specifies the incident angle .alpha. when the intensity of the
plasmon scattered light 94 becomes maximum as the enhancement angle
on the basis of the data, and sets the incident angle .alpha. of
the excitation light 91 to the enhancement angle. Also, the
enhancement angle is determined on the order of approximately 0.1
degrees.
[0089] Thereafter, by the control of the control arithmetic unit
50, the light projection unit 10 irradiates the region of the
reflective surface 73 corresponding to the reaction site 77 of the
inspection chip 60 with the excitation light 91 at the incident
angle .alpha. set to the enhancement angle. At the same time, the
detection unit 40 detects the amount of light of the same
wavelength as that of the fluorescence 93. The control arithmetic
unit 50 records the light amount of the light measured by the
detection unit 40 as the optical blank value.
[0090] Thereafter, the measuring buffer solution in the inspection
chip 60 is recovered by the liquid delivery/conveyance unit 30, and
a sample to be measured is newly supplied into the inspection chip
60. Meanwhile, as the sample to be measured, a sample collected
directly from an inspection subject may be used, or a sample
obtained by diluting the sample directly collected from the
inspection subject with the sample diluting solution may be
used.
[0091] Next, a primary reaction for allowing the substance to be
detected present in the sample to bind to the first capturing body
exposed to the reaction site 77 is performed (step S30).
Specifically, by control of the control arithmetic unit 50, the
liquid delivery/conveyance unit 30 moves the target inspection chip
60 to the position 10c (refer to FIG. 3) of the biochemical
inspection system A, and mount the inspection chip 60 on the
rotating body of the stirring device corresponding to the position
10c. Then, the vibration unit 10 stirs the liquid in the inspection
chip 60. At that time, the substance to be detected present in the
sample specifically binds to the first capturing body exposed to
the reaction site 77, so that this is captured by the first
capturing body and remains on the reaction site 77.
[0092] After a sufficient time for the reaction elapses, in order
to clean the inside of the inspection chip 60, the sample to be
measured in the inspection chip 60 is recovered by the liquid
delivery/conveyance unit 30, and the cleaning solution is newly
supplied into the inspection chip 60. At that time, since the
liquid in the inspection chip 60 is continuously stirred by the
vibration unit 10, the substance to be detected, impurities and the
like which are nonspecifically adsorbed in the inspection chip 60
are removed.
[0093] Thereafter, the cleaning solution in the inspection chip 60
is recovered by the liquid delivery/conveyance unit 30, and the
labeling solution is newly supplied into the inspection chip
60.
[0094] Next, a secondary reaction for assigning the fluorescent
label to the substance to be detected captured by the first
capturing body is performed (step S40). Specifically, by control of
the control arithmetic unit 50, the liquid delivery/conveyance unit
30 moves the target inspection chip 60 to the position 10d (refer
to FIG. 3) of the biochemical inspection system A, and mount the
inspection chip 60 on the rotating body of the stirring device
corresponding to the position 10d. Then, the vibration unit 10
stirs the liquid in the inspection chip 60. The second capturing
body labeled with fluorescence is present in the labeling solution,
and the second capturing body specifically binds to the substance
to be detected at a site different from a site of the substance to
be detected specifically binding to the first capturing body, so
that the substance to be detected is indirectly labeled with the
fluorescence by specifically binding to the second capturing body.
Meanwhile, the type of the second capturing body is not especially
limited as long as this may specifically bind to the substance to
be detected at the site different from the site of the substance to
be detected specifically binding to the first capturing body. For
example, the second capturing body may be a biomolecule specific to
the substance to be detected or a fragment thereof. Also, the
second capturing body may be formed of one molecule, or may be a
complex formed by binding two or more molecules.
[0095] After a sufficient time for the reaction elapses, in order
to clean the inside of the inspection chip 60, the labeling
solution in the inspection chip 60 is recovered by the liquid
delivery/conveyance unit 30, and the cleaning solution is newly
supplied into the inspection chip 60. At that time, since the
liquid in the inspection chip 60 is continuously stirred by the
vibration unit 10, the second capturing body, impurities and the
like which are nonspecifically adsorbed in the inspection chip 60
are removed.
[0096] Thereafter, the cleaning solution in the inspection chip 60
is recovered by the liquid delivery/conveyance unit 30, and the
measuring buffer solution is newly supplied into the inspection
chip 60.
[0097] Next, the fluorescence value measurement for measuring the
fluorescence value from the substance to be detected labeled with
the fluorescence is performed (step S50). Specifically, by the
control of the control arithmetic unit 50, the liquid
delivery/conveyance unit 30 arranges the target inspection chip 60
in the position 10e (refer to FIG. 3) of the biochemical inspection
system A, and the light projection unit 10 irradiates the region of
the reflective surface 73 corresponding to the reaction site 77 of
the inspection chip 60 with the excitation light 91 at the incident
angle .alpha. set to the enhancement angle. At the same time, the
detection unit 40 detects the amount of light of the same
wavelength as that of the fluorescence 93. The control arithmetic
unit 50 records the light amount of the light measured by the
detection unit 40 as the fluorescence value. At that time, when a
liquid level of the liquid (measuring buffer solution) in the
liquid accommodation unit 65 is close to the position of the
reaction site 77, the fluorescence reflected or refracted by the
liquid surface might also be detected by the detection unit 40, so
that from the viewpoint of detection accuracy, the reaction site 77
is preferably located below the liquid level of the liquid
(measuring buffer solution) in the liquid accommodation unit 65 and
in a position distant from the liquid level. Therefore, the
measuring buffer solution at this step may be supplied by a larger
amount than that of the liquid used at other steps.
[0098] Thereafter, the inspection chip 60 is disposed by the
control of the control arithmetic unit 50, and the control
arithmetic unit 50 subtracts the optical blank value obtained at
step S20 from the obtained fluorescence value to calculate a signal
value correlated with the amount of the substance to be detected.
The control arithmetic unit 50 may also further convert the signal
value into the amount, concentration and the like of the substance
to be detected on the basis of a calibration curve created in
advance.
[0099] After that, the inspection ends. At above-described steps,
the biochemical inspection system A may measure the presence or
amount of the substance to be detected in the sample.
[0100] Meanwhile, at step S20 described above, the incident angle
.alpha. of the excitation light 91 is set to the enhancement angle,
but the incident angle .alpha. of the excitation light 91 may be
set to the resonance angle in place of the enhancement angle. In
this case, at step S20, the light projection unit 10 irradiates the
region of the reflective surface 73 corresponding to the reaction
site 77 of the inspection chip 60 with the excitation light 91
while scanning the incident angle .alpha.. At the same time, the
detection unit 40 detects the light amount of the reflected light
92. The control arithmetic unit 50 obtains data including a
relationship between the incident angle .alpha. of the excitation
light 91 and the light amount of the reflected light 92, specifies
the incident angle .alpha. when the light amount of the reflected
light 92 becomes minimum as the resonance angle on the basis of the
data, and sets the incident angle .alpha. of the excitation light
91 as the resonance angle.
[0101] The present application claims priority based on JP
2017-025823 A filed on Feb. 15, 2017. The contents described in the
specification and drawings of the application are entirely
incorporated herein by reference.
REFERENCE SIGNS LIST
[0102] 10 Vibration unit [0103] 10a, 10b, 10c, 10d, 10e Position
[0104] 20 Light projection unit [0105] 30 Liquid
delivery/conveyance unit [0106] 40 Detection unit [0107] 50 Control
arithmetic unit [0108] 51 CPU [0109] 52 Light projection control
unit [0110] 53 Liquid delivery drive control unit [0111] 54 Liquid
delivery movement control unit [0112] 55 Conveyance control unit
[0113] 56 Detection control unit [0114] 57 Arithmetic unit [0115]
60, 60a, 60b, 60c, 60d, 60e, 60x, 60y Inspection chip [0116] 61
Well main body [0117] 62 Side wall member [0118] 63 First opening
[0119] 64 Second opening [0120] 65 Liquid accommodation unit [0121]
66 Bottom surface structure [0122] 66a, 66b Tip end [0123] 71 Prism
[0124] 72 Incident surface [0125] 73 Reflective surface [0126] 74
Emitting surface [0127] 75 Metal film [0128] 76 Capturing film
[0129] 77 Reaction site [0130] 91 Excitation light [0131] 92
Reflected light [0132] 93 Fluorescence [0133] 94 Plasmon scattered
light [0134] 99 Rotating body [0135] A Biochemical inspection
system [0136] c Symmetry center [0137] x Tip end position [0138]
G1, G2 Center of gravity [0139] 60 Incident angle
* * * * *